Boerking, I know BC breeders who have imported bucks in the past. I don't know if it's still permitted, but these people would probably be willing to walk you through the process if it can still be done. If you're interested, say so, and I'll PM you their contact info.
Not going to be easy. They closed the borders up with the mad cow scare years ago and have keep em tight. I wanna say if they do allow it, it will be a long quarantine period to deal with. If you have any livestock vets in your area they should know for sure.
I know a gal that sent a buck to Canada last year and another guy that sent some bucks this year so it can be done. Contact your agriculture agency to find out what the goat needs. He will most likely need to be tested for a number of diseases (such as TB, Brucellosis and Q-Fever). I do know that he will need to be tattooed in his flank with USA (showing where he came from) and will need international health papers. If the herd he is coming from is not enrolled in the Voluntary Scrapies Eradication Program for x number of years then he will likely need to be quarantined for a little while. I don't think it is as hard as people think. I think the US is more strict on importing any animals than Canada is (goats can not be imported from Canada to the US, but semen can). It would also be a good idea to contact the owner of the animal and possibly contact the USDA so they can help you figure out everything that needs to be done to the goat in the US.
When I recently sold one of my bucklings going to Alaska, the question was asked if the people I sold too was going through Canada. Luckily for me the answer was no. If it had been yes, then a lot if testing etc, and the vet would need to come to my farm to inspect things... There is a whole lot to it, as my vet let me know like 10 things that needed to be done. It can be done, but like others stated not easy and VERY expensive..